: the mean time that is associated with the prime meridian of Greenwich, England, and historically used as the prime basis of standard time throughout the world
The British traditionally used Greenwich Mean Time, calculated from the meridian running through Greenwich, a borough of London.—The New York Times
Coordinated Universal Time is what used to be called Greenwich Mean Time, but the new name doesn't make it any more universal than it ever was, and it remains a time zone centered in Britain.—Natalie Angier
—abbreviation GMT
called also Greenwich Time
compare coordinated universal timeCite this Entry
“Greenwich Mean Time.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/Greenwich%20Mean%20Time. Accessed 31 Mar. 2025.
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